Mill hole and tunnel lining structure



June 17, 1969 J. BARDSWICH MILL HOLE AND TUNNEL LINING STRUCTURE Filed Jan. 16, 1967 United States Patent U.S. Cl. 138-100 5 Claims ABSTRACT OF THE DISCLOSURE A tubular liner for mill holes and tunnels in the mining and tunnelling industries comprising a segment assembly wherein the lateral joint planes are staggered from segment to segment along the length of a continuous longitudinal joint of the tube. The longitudinal joint is spliced together as by means of a connector bar extending from end to end of the longitudinal joint and bolted to each of the segment end portions along the joint.

BACKGROUND OF THE INVENTION Field 0 the invention The invention relates to the conventional field of mill hole and tunnel lining structures as required in the mining and tunnelling industries. These liners are of tubular form and necessarily composed of a plurality of segments which are fitted together in the field to form a composite tube assembly of any required length.

Description of the prior art The conventional liner tube assembly comprises a plurality of cylindrical sections arranged in end to end axial relationship and each comprising a plurality (usually three) segments. The longitudinal joints of each section are staggered with respect to those of adjoining sections. The lateral joint between each pair of contiguous sections is continuous and lies in a single plane.

SUMMARY OF THE INVENTION The invention resides in a lining structure for mill holes and tunnels comprising two series of arcuate sheets, one for each end of the structure. The sheets of each series, when placed in end to end relationship, have a cylindrical formation. The sheets of each series are of differing axial extent whereby, in cylindrical formation, with an arcuate edge of each plate in coplanar relationship, the other arcuate edges are in staggered planes. One or more intermediate series of arcuate sheets of substantially uniform size and configuration are provided, the sheets of each series having in end to end relationship, a cylindrical formation. The assembled structure thus has all of its circumferential joints in discontinuous form since each pair of meeting arcuate edges is in a plane differing from all others. The longitudinal joints in the assembled structure are continuous from end to end thereof. The assembled series of sheets are secured together in any suitable manner. A preferred securing means comprises a connector bar or cover strip overlying each longitudinal joint on the inner surface of the structure and fixed to the respective edge portions of the adjoining sheets.

The use of a circumferentially staggered joint arrangement with a continuous wear and cover strip over the vertical or longitudinal joints provides a greatly improved distribution of stress and wear from segment to segment of the assembled structure. Weldments, one of the most significant areas of failure, are substantially eliminated. Moreover, absence of projecting weldments results in a more effective nesting of the segments with reduced bulk in transport and storage. Because of improved stress and wear distribution, lighter plates can be used, thus reducing costs of material, transportation, and labor required for assembly.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a side elevation of an assembled structure in accordance with the invention, and

FIGURE 2 is a plan view.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, each end portion of the tubular assembly illustrated comprises a series 9 of arcuate plates. In the modification shown, there are three plates 10, 11 and 12 in each series, the arcuate extent of each plate being whereby they form a continuous circumferential wall. Each plate has a pair of opposed arcuate side edges 13, 14, 15, respectively, and a pair of opposed straight end edges 16, 17, 18, respectively.

The plates 10, 11, 12 are of varying width or axial extent. Thus, plate 10 is relatively narrow, plate 12 is relatively wide, and plate 11 is of intermediate Width.

One arcuate edge 13, 14, 15 of each plate is arranged 'm planar relation to arcuate edges of the other two plates to constitute a plane end edge of the assembly. The other arcuate edges of the plates will, of course, be in circumferentially staggered relation.

One or more intermediate series 19 of arcuate plates 20 are arranged between the two series 9. As shown, there are three plates 20 in each series, each having an arcuate extent of 120. Each plate 20 has a pair of arcuate edges 21 and a pair of end edges 22. The plates 20 are substantially uniform in size and configuration.

In associating the plates 20 of an adjoining series 19 with the plates 10, 11 and 12, an arcuate edge 21 forms a circumferentially extending joint with an arcuate edge 13, 14 or 15. However, because of the circumferential stagger of the latter edges, the resulting circumferential joint will be discontinuous, that is; the portion of the complete joint formed by edges 21 and 13 will be in a plane different from that of the joint portion formed by edges 21 and 14, and the joint portion formed by edges 21 and 15 will be in still another plane. Moreover, this pattern of discontinuous circumferentially jointing Will continue throughout the structure.

Each group of meeting end edges 16, 17, 18 and 22 of the plates will constitute, as shown, a longitudinally extending joint 23 which extends in a straight line from end to end of the structure. In the modification shown, there are three such joints.

The plates of the assembled structure are secured together to provide a rigid tubular unit in any suitable manner. However, in accordance with a further feature of the invention, the assembly securing means is preferably constituted in a manner now to be described.

A wear strip of connector bar 24 is applied to the inner surface area of each joint 23, the strip being coextensive in length with the joint. The strip is secured as by bolts 25 and nuts 26, to the end portions of each plate 10, 11, 12 and 20 that it traverses. Preferably, the heads of the bolts 25 are countersunk in the strip to avoid the presence of any sharp or pronounced projections on the inner surface of the tube. The strip 24 is, of course, relatively thin and does not present any objectionable obstruction.

A bracket 27 may also be provided to bridge each circumferential joint portion formed by each pair meeting arcuate edges of the plates, each bracket being located approximately midway between the ends of the plates to which it is applied. Each bracket is applied to the outer surface of the structure and is secured to the plates by means of bolts 28 and nuts 29. The heads of the bolts are preferably countersunk in the inner surfaces of the plates.

It will be apparent that assembly of the structure will be carried out in the field by selecting appropriate lengths of connector bars 24 and securing successively thereto the segments or plates.

I claim:

1. A lining structure for mill holes and tunnels which comprises (a) two series of arcuate sheets,

(b) said sheets of each said series having in end to end relationship a cylindrical formation,

(c) said sheets of each said series having differing axial extent,

((1) a plurality of series of arcuate sheets of substantially uniform size and configuration having in end to end relationship a cylindrical formation,

(e) each said sheet having a pair of arcuate side edges and a pair of straight end edges,

(f) all of said series of sheets having a tubular formation in assembly,

(g) said tubular formation having a continuous planar edge at each end thereof constituted by said arcuate edges of sheets of one of said two series,

(h) the remaining arcuate edges of said sheets being in planes different from that of each other,

(i) said tubular formation having a plurality of discontinuous circumferential joints each constituted by a plurality of said arcuate edges,

(j) said tubular formation having a plurality of planar longitudinal joints each extending from end to end thereof and each constituted by a plurality of said end edges,

(k) a plurality of connector bars each having a length substantially equal to that of said tubular formation, and

(1) means for securing each said connector bar to a portion of each of said plates adjoining one of said longitudinal joints.

2. A lining structure for mill holes and tunnels which comprises (a) a pair of end cylindrical sections,

(b) a plurality of intermediate cylindrical sections,

() each said section comprising a series of arcuate sheets,

(d) each sheet of each said series having a pair of straight end edges in substantial engagement with an end edge of an adjoining one of said sheets, and a pair of arcuate side edges,

(e) said structure having a pair of continuous planar end edges each constituted by a plurality of said arcuate side edges of one of said end sections,

(f) said sheets of each said end section series being of different axial extent,

(g) said sheets of each said intermediate section series being of substantially uniform size and configuration,

(b) said structure having a plurality of discontinuous circumferential joints each constituted by a plurality of said arcuate edges,

(i) said structure having a plurality of planar longitudinal joints each extending from end to end thereof and each constituted by a plurality of said end edges,

(j) a connector bar applied to each said longitudinal joint and extending from end to end thereof on the interior surface of said structure, and

(k) said connector bar having means fixing it to each of said plates whose end edges constitute said longitudinal joint.

3. A lining structure as defined in claim 2, including a connector bracket fixed to each pair of adjoining ones of said plates and bridging the circumferential joint portion therebetween.

4. A lining structure as defined in claim 2, wherein said fixing means comprises a plurality of bolts each having a head countersunk in said bar.

5. A lining structure as defined in claim 3, each said connector bracket being applied to the outer surface of said structure, and including means for fixing each said bracket to a pair of said plates comprising bolts having heads countersunk in said plates.

References Cited UNITED STATES PATENTS 979,146 12/1910 Foster 138l00 1,197,140 9/1916 Mathews 138l00 X 2,065,368 12/1936 Freeze 138-100 PATRICK D. LAWSON, Primary Examiner. 

